Remove calls to clone from types that implement Copy

Clippy emits:

  warning: using `clone` on type `blockdata::transaction::OutPoint`
  which implements the `Copy` trait

Remove calls to `clone` from types that implement `Copy`.

src/blockdata/block.rs

@@ -521,7 +521,7 @@ mod tests {
         }
 
         // test with modified header
-        let mut invalid_header: BlockHeader = some_header.clone();
+        let mut invalid_header: BlockHeader = some_header;
         invalid_header.version += 1;
         match invalid_header.validate_pow(&invalid_header.target()) {
             Err(BlockBadProofOfWork) => (),

src/util/bip158.rs

@@ -554,7 +554,7 @@ mod test {
             let mut si = scripts.iter();
             for tx in block.txdata.iter().skip(1) {
                 for input in tx.input.iter() {
-                    txmap.insert(input.previous_output.clone(), Script::from(Vec::from_hex(si.next().unwrap().as_str().unwrap()).unwrap()));
+                    txmap.insert(input.previous_output, Script::from(Vec::from_hex(si.next().unwrap().as_str().unwrap()).unwrap()));
                 }
             }
 
@@ -562,7 +562,7 @@ mod test {
                                         |o| if let Some(s) = txmap.get(o) {
                                             Ok(s.clone())
                                         } else {
-                                            Err(Error::UtxoMissing(o.clone()))
+                                            Err(Error::UtxoMissing(*o))
                                         }).unwrap();
 
             let test_filter = BlockFilter::new(filter_content.as_slice());